Question: give me the name of determination method for Belo Horizonte has population as 2.50256e+06?
Paraphrase: How was Belo Horizonte's population count of 2.50256e+06 determined?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q42800 p:P1082 ?s . ?s ps:P1082 ?x filter(contains(?x , '2.50256e+06')) . ?s pq:P459 ?value}